Channel bed hydraulic presses are used in virtually all machine shops, vehicular repair facilities and bearing, transmission, clutch, engine, drive shafts, pumps, etc. manufacturing facilities. Their primary function is to assemble/disassemble press fitted articles such as bearings, clutches, pulleys, transmissions and the like. Channel bed presses generally have two separated channels extending horizontally between two vertical support members and joined at the ends with long bolts. A hydraulic cylinder is supported by a third beam member located above the two channel cross members. The hydraulic beam member and channel bed members are moveable in relationship to each other to adjust to the height of the article being pressed and lineal extension capability of the hydraulic cylinder. Such presses are also known as "H" frame channel bed presses. In operation, separated cross plates are placed over the two channel bed members in such manner that an opening is formed to accommodate the article component that is being pressed from the article's shell. The article is positioned on the crossplate members over the opening and directly under the hydraulic ram. A fitting adapted to the article may be inserted between the article and hydraulic ram. The hydraulic mechanism is activated to apply pressure to the article component to force it out of the article's shell. The reverse, i.e. pressure is applied to the article component to force it into the article shell for assembly of an article.
In many instances articles that have been in service, such as bearings, work harden and become brittle; also in the chemical industry exposure to chemicals may fuse shafts to inner bearing races. Such embrittlement is not obvious even to the experienced operator. Thus, when pressure is applied to separate components they shatter with bullet-like force showering the surrounding area with high speed projectiles which may potentially injure the press operator. Press manufacturing companies literature suggests shielding the press area with plywood and or canvas drop shields, steel collars and the like. These function as shields but hide the article being pressed from the operator's view and control. Therefore many presses are operated without shielding resulting in many injuries and workman's compensation claims.